Residents gather at Shadow Lakes in Hopewell to discuss possible new cracker plant in Potter Township

A plan to build a huge new petrochemical plant in western Pennsylvania is making progress, Shell Oil Co. officials said Wednesday - but there's still no guarantee the multi-billion dollar project will actually be constructed.

That message of optimism and caution was stressed by company officials to about 200 people who showed up for the first of two public meetings regarding a proposed plant site about 30 miles northwest of Pittsburgh.

Shell has an option to purchase a 300-acre industrial site on the Ohio River and demolition of a zinc factory that was there has already begun. But Shell general manager Dan Carlson said that doesn't necessarily mean the so-called ethane cracker plant will be built. In some other states - Colorado, for example - Shell invested tens of millions of dollars in proposed projects before deciding to shut them down.

Carlson said the company has signed long-term contracts with about 10 energy companies to supply the proposed plant. It would convert ethane from bountiful Marcellus and Utica shale oil and natural gas into more profitable chemicals used to produce plastics, tires, fertilizer, and other products.

Carlson said it's hard to predict when the decision on whether to build the plant will be made, but it could come in the next one or two years. For now, the company is happy with the response from local communities.

"We're just really glad to see that there's so much excitement and enthusiasm," Carlson said. "I think people recognize the impact this project could have" on the regional economy.

Suzanne Mycyk and her husband Bo, who live in nearby Ambridge, said they both hope Shell builds the plant and most of their friends feel the same way.

"I want this area to succeed and be thriving like it used to," Suzanne said, referring to the time before the local steel industry went into steep decline. "To me Shell Corp. would be a fantastic shot in the arm," Bo Mycyk added. Both attended to learn more about Shell's plans.

The meeting was held at a county club a few miles away from the proposed plant site. Shell displayed a map of the site and answered questions from individuals one-on-one.

In 2012, Gov. Tom Corbett signed legislation that could give Shell tax credits worth $1.7 billion or more for 25 years, beginning in 2017, if the plant is built.

Shell, which has its U.S. headquarters in Houston, has estimated that a new cracker plant could employ several hundred people, lead to the growth of related businesses and create up to 10,000 construction jobs.

Carlton Vreen, a local pastor, said many people are excited about Shell's plans, but they have questions, too.

"What will be the impact to the local community as far as jobs and roads?" Vreen asked. "How are they going to update the infrastructure?"

Vreen also wondered if Shell will offer local people training for new jobs in the chemical industry.

Shell officials say they're already working on plans to upgrade nearby highways, but many questions can't be answered before a final decision to invest is made. And even if that happens, the enormous plant would take about four years to build.

It's also clear that the western Pennsylvania project is competing not just with other states, but other nations. While the Gulf Coast has been the major U.S. center for ethane cracker plants for more than 50 years, there are similar operations in other nations, too.

Shell has recent major projects in Iraq, Malaysia, Brazil, Qatar, and Africa.

Israeli Prime Minister Benjamin Netanyahu warned Tuesday that a proposed agreement between world powers and Iran was "a bad deal" that would not stop Tehran from getting nuclear weapons -- but would rather pave its way to getting lots of them and lea...